I Don't Get It

I don't get what the infants vs. blastocysts hypo is supposed to prove. Sure, our intuition is that the fireman would choose to rescue the infants. I suppose that means we value infants more than blastocysts. So what? Does that mean we should not regard blastocysts as human persons who should be protectected from a decision to eliminate them? Or is the hypo to be taken to mean that because we would value infants more than blastocysts, then we should feel free to honor the choice to eliminate that form of human life when it is not necessary to do so?  If we can pick and choose among different forms of human life, what is the limit? Apparently,  we can value the healthy more than the disabled, the young more than the elderly, the Aryan more than the Jew and so on, and make life and death choices accordingly For example, who would the Nazi fireman choose to save -- the Aryan or the Jew?  All the hypo "proves" is that people tend to value some forms of life more than others. How does that resolve the ethical problem created by one who chooses to end an innocent life because it is unwanted?

--Mark